This is because the top floor ceiling is no longer the air barrier for the house the spray foam at the roof deck underside in the attic is the air barrier.
Spray foam metal roof attic.
A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits but then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents.
We ll add a vapor barrier so the moist air does not flow up through the insulation and condense on the roof.
This is a liftime metal roof.
The problem with using.
Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly.
This alternative to traditional building insulation fiberglass can be applied into wall cavities holes concrete slabs and even onto roof tiles and.
Earlier this year i got a question about a home that had spray foam insulation in the attic.
Shingle warranty after spray foam attic insulation.
But a preinstalled membrane may be even more effective at removing condensation.
Traditionally we ve insulated the roof panel to try and keep the temperature on the panel from reaching the dew point.
The biggest benefit of spray foam insulation is its air sealing quality so if air is infiltrating into a spray foam attic then the installers missed some spots and need to go back and make it right.
The unvented attic space is considered the most effective and up to date building practice particularly by the spray foam industry.
Nothing unusual about that.
Serving as both an air sealant and an insulator spray foam is estimated to reduce the standard hvac sizing by about 35 on average.
Benefits and pitfalls of spray foam insulation according to the us environmental protection agency epa spray foam is recognized as a premier alternative to the batt insulation of years past.
Spray polyurethane foam is a chemical product that is created by two materials isocyanate and polyol resin that will react with each other when they are mixed and will expand up to 30 to 60 times its liquid volume as it is sprayed in place.
Moisture from the house.
In an unvented attic penetrations through the ceiling directly below the attic do not need to be air sealed.